“We reached Mr. March’s fazenda early in the forenoon.” Gardner wrote in his diary. “It being Christmas-day, we found his slaves, who amount to 100 in all, performing a native dance in the yard before the house. His estate embraces an extent of country containing sixty-four square miles. The greater part of it is still covered by virgin forests ; what is cleared of it consists of pasture land, and several small farms for the cultivation of Indian corn, ﬁagrens (French beans), and potatoes. Plentiful crops are yielded by the two former, but the produce of the latter is neither so abundant nor so good as it is in England. He has also near to his house a large garden, under the management of a French gardener, in which all the European fruits and vegetables grow tolerably well. Many of these he has been at much trouble and expense in introducing from the Old World. From this garden he sends regular supplies of vegetables to the Rio market, and they are by far the best that are to be found in it. “

From here over the next few months Gardner set out on regular expeditions exploring the region for twenty or thirty miles in each direction.

Laurus nobilis flowers

The various species of Laurus form ﬁne large trees, and when growing, as they often do, in an open part of the forest, they remind the European of the oaks of his native country. They ﬂower in April and May, loading the air with the rich perfume of their small white blossoms. Their ripened fruit forms the principal food of the Jacutinga, (Penelope Jacutinga Spix) a ﬁne large game bird.

Penelope Jacutinga Spix

Some of the largest trees of the forest are species of Ficus ; one, with an enormous height and thickness of stem, is called by English here the buttress tree, from several large thin plates which stand out from the bottom of the trunk. They begin to jut out from the stem at the height of ten or twelve feet from the bottom, and gradually increase in breadth till they reach the ground, where they are connected with the large roots of the tree. At the surface of the ground these plates are often ﬁve feet broad, and through out not more than two inches thick.

The large Cassia have a striking appearance when in ﬂower ; and as an almost equal number of large trees of Lasiandra fontanesiana [now renamed Tibouchina] and other species belonging to the same natural order are in bloom at the same time, the forests are then almost one mass of yellow and purple from the abundance of these ﬂowers.

When rainforests are not protected

Wild plants have provided humans with everything from quinine, aspirin and morphine to numerous cancer and HIV-fighting drugs. Seventy percent of the plants identified as having anti-cancer characteristics by the US National Cancer Institute are found only in the tropical rainforest.

When rainforests vanish, they take with them hundreds of as yet undiscovered plant species, many of which may have had life-saving medicinal properties. One near recent miss was Calanolide A, a compound with significant anti-HIV effects. Calanolide A is derived from Calophyllum lanigerum var austrocoriaceum, a very rare member of the Guttiferae or mangosteen family. Samples were first collected in 1987 on a National Cancer Institute (NCI)-sponsored expedition in Sarawak. Having discovered that the plant was active against HIV, excited researchers rushed back to the original kerangas forest near Lundu … but the tree was no longer there.

The tree was gone — likely felled by locals for fuelwood or building material. The disappearance of the tree lead to a furious search by botanists for further specimens. Good news finally came from the Singapore Botanic Garden which had several plants collected by the British over 100 years earlier. Sarawak banned the felling and export of Calophyllum shortly thereafter.

The importance of Gardner’s explorations

What of the many medicinal trees and plants discovered by Gardner? A team of Kew researchers decided to revisit the collection. They searched George Gardner׳s exhaustive Catalogue of Brazilian Plantsdeposited in the archives of the Royal Botanic Gardens, Kew, UK.

Each plant was re-identified and/or updated by consulting the preserved botanical collections that Gardner gave to the Herbarium of the Royal Botanic Gardens, Kew, and expert inspection of other collections to which Gardner had given duplicates. The team scoured the PubMed database for whatever pharmacological studies had been done on the plants. Gardner׳s diary entries and published letters were consulted and 63 useful plants were recorded from the Catalogue and a further 30 from Gardner׳s book Travels in the Interior of Brazil.

Take just one tree discovered by Gardner: Cissus erosa. The French Guianan Palikur use the stem and leaves to make a plaster with pain killing and healing properties that they apply to the ulcers of leishmaniasis and to wound s inflicted by of river rays of Paratrygon species.

The stem sap of is drunk to reduce fever. Crushed leaves are applied externally to treat snakebite, ulcers and thrush. The liana is crushed and rubbed on centipede bites by the Surinam Akuriyo. (Shown here Scolopendra viridicornis viridicornis, two-thirds life size.)

Of the recorded names in the Catalogue, 46 (73%) could be identified to species by consulting specimens collected by Gardner and held at Kew. Thirty-six different traditional uses were registered for the identified plants, the most common being as febrifuges, to treat venereal complaints and as purgatives. Fewer than 50% of these species have been the focus of published pharmacological studies, yet for those which have been thus investigated, the efficacies reported by Gardner were confirmed.

The data recorded by Gardner, the Kew study rather blandly concludes, represent a rich, relatively unexplored source of information regarding the traditional uses of Brazilian plants which merits further investigation. Yes, because the forests he explored have largely all gone. Get on with it!